Question

数学 七年级 下册

(m+2n)(m-2n)=
(2n+5)(n-3)=
(x+2y)^2=
(ax+b)(cx+d)=
(x+y)(a+2b)=
(2a+3)(3/2b+5)=
(2x+3)(-x-1)=
(-2m-1)(3m-2)=
(x+y)^2=
(-2x+3)^2=
要过程。

Answer 1

(m+2n)(m-2n)=m^2-4n^2
(2n+5)(n-3)=2n^2-n-15
(x+2y)^2=x^2+4xy+4y^2
(ax+b)(cx+d)=acx^2+(ad+bc)x+bd
(x+y)(a+2b)=ax+ay+2bx+2by
(2a+3)(3/2b+5)=3ab+9/2b+10+15
(2x+3)(-x-1)=-2x^2-5x-1
(-2m-1)(3m-2)=-6m^2+m-3
(x+y)^2=x^2+2ay+y^2
(-2x+3)^2=4x^2-12x+9